AU2019313768B2 - Unmanned vehicle control system, unmanned vehicle, and unmanned vehicle control method - Google Patents

Abstract

This unmanned vehicle control system comprises: a travel condition data acquisition unit which acquires travel condition data that defines the travel conditions of an unmanned vehicle including the target travel speed and target direction of the unmanned vehicle at each of a plurality of travel points; a travel condition change unit which outputs a change command for changing the travel conditions defined by the travel condition data on the basis of the difference in the target direction at the plurality of travel points; and a travel control unit which outputs a control command for controlling the travel of the unmanned vehicle on the basis of the change command.

Description

DESCRIPTION UNMANNED VEHICLE CONTROL SYSTEM, UNMANNED VEHICLE, AND UNMANNED VEHICLE CONTROL METHOD

Field

[0001] The present invention relates to an unmanned

vehicle control system, an unmanned vehicle, and an

unmanned vehicle control method.

Background

[0002] Any discussion of the prior art throughout the

specification should in no way be considered as an

admission that such prior art is widely known or forms part

of common general knowledge in the field.

[0002a] In a work site in a wide area such as a mine, an

unmanned vehicle that travels in an unmanned state is

sometimes used.

Patent Literature

[0003] Patent Literature 1: JP 2010-073080 A

Summary

[0004] An unmanned vehicle travels on a work site based

on travel condition data transmitted from a control

facility. The unmanned vehicle travels according to a

target travel course specified by the travel condition data.

It is preferable that the unmanned vehicle travel at a high

speed in order to suppress a decrease in productivity at

the work site. On the other hand, the unmanned vehicle is

likely to deviate from the target travel course depending

on travel conditions. If the unmanned vehicle deviates

from the target travel course and the operation of the

unmanned vehicle is stopped, the productivity at the work

site is likely to decrease.

[0004a] It is an object of the present invention to

overcome or ameliorate at least one of the disadvantages of

the prior art, or to provide a useful alternative.

[00051 An aspect of the present invention aims to

suppress a decrease in productivity while ensuring safety

at a work site where an unmanned vehicle operates.

Solution to Problem

[00061 According to an aspect of the present invention,

an unmanned vehicle control system comprises: a travel

condition data acquisition unit that acquires travel

condition data specifying a travel condition of an unmanned

vehicle, the travel condition data including a target

travel speed and a target azimuth of the unmanned vehicle

at each of a plurality of travel points; a travel condition

change unit that outputs a change command to change the

travel condition specified by the travel condition data

based on a difference in the target azimuth among the

plurality of travel points; and a travel control unit that

outputs a control command to control traveling of the

unmanned vehicle based on the change command.

[0006a] According to a further aspect of the present

invention, there is provided an unmanned vehicle control

system comprising: a travel condition data acquisition unit

that acquires travel condition data specifying a travel

condition of an unmanned vehicle, the travel condition data

including a target travel speed and a target azimuth of the

unmanned vehicle at each of a plurality of travel points; a

travel condition change unit that outputs a change command

to change the travel condition specified by the travel

condition data based on a difference in the target azimuth

among the plurality of travel points; and a travel control

unit that outputs a control command to control traveling of

the unmanned vehicle based on the change command, wherein

the travel condition change unit outputs the change command

when the difference in the target azimuth is equal to or

larger than a threshold, and the travel control unit

2a

outputs the control command such that the unmanned vehicle

travels based on the travel condition data when the

difference in the target azimuth is smaller than the

threshold.

[0006b] According to a further aspect of the present

invention, there is provided an unmanned vehicle control

method comprising: acquiring travel condition data that

specifies a travel condition of an unmanned vehicle, the

travel condition data including a target travel speed and a

target azimuth of the unmanned vehicle at each of a

plurality of travel points; outputting a change command to

change the travel condition specified by the travel

condition data based on a difference in the target azimuth

among the plurality of travel points; and outputting a

control command to control traveling of the unmanned

vehicle based on the change command, wherein the change

command is output when the difference in the target azimuth

is equal to or larger than a threshold, and wherein the

control command is output such that the unmanned vehicle

travels based on the travel condition data when the

difference in the target azimuth is smaller than the

threshold.

[0006c] Unless the context clearly requires otherwise,

throughout the description and the claims, the words

"comprise", "comprising", and the like are to be construed

in an inclusive sense as opposed to an exclusive or

exhaustive sense; that is to say, in the sense of

"including, but not limited to".

[0007] According to an aspect of the present invention,

it is possible to suppress the decrease in productivity

while ensuring the safety at the work site where the

unmanned vehicle operates.

Brief Description of Drawings

2b

[00081 FIG. 1 is a view schematically illustrating

examples of a management system and an unmanned vehicle

according to an embodiment.

FIG. 2 is a view schematically illustrating the

unmanned vehicle and a travel path according to the

embodiment.

FIG. 3 is a functional block diagram illustrating an

unmanned vehicle control system according to the embodiment.

FIG. 4 is a schematic view for describing a travel

condition of the unmanned vehicle according to the

embodiment.

FIG. 5 is a schematic view for describing the travel

condition of the unmanned vehicle according to the

embodiment.

FIG. 6 is a schematic view for describing a threshold

Docket No. PKOA-20376-US,AU: Final draft 3

according to the embodiment.

FIG. 7 is a flowchart illustrating an unmanned vehicle

control method according to the embodiment.

FIG. 8 is a block diagram illustrating an example of a

computer system according to the embodiment.

Description of Embodiments

[00091 Hereinafter, embodiments of the present invention

will be described with reference to the drawings, but the

present invention is not limited thereto. Components of

the embodiments to be described below can be combined as

appropriate. In addition, there is also a case where some

components are not used.

[0010] [Management System]

FIG. 1 is a view schematically illustrating examples

of a management system 1 and an unmanned vehicle 2

according to the present embodiment. The unmanned vehicle

2 refers to a work vehicle that travels in an unmanned

state based on a control command without depending on a

driving operation performed by a driver.

[0011] The unmanned vehicle 2 operates at a work site.

In the present embodiment, the work site is a mine or a

quarry. The unmanned vehicle 2 is a dump truck that

travels at the work site and transports a cargo. The mine

refers to a place or a business site where a mineral is

mined. The quarry refers to a place or a business site

where a rock is mined. As the cargo transported to the

unmanned vehicle 2, ore or dirt excavated in the mine or

the quarry is exemplified.

[0012] The management system 1 includes a management

device 3 and a communication system 4. The management

device 3 includes a computer system and is installed in a

control facility 5 at the work site. A controller exists

in the control facility 5. The communication system 4

Docket No. PKOA-20376-US,AU: Final draft 4

performs communication between the management device 3 and

the unmanned vehicle 2. The management device 3 is

connected with a wireless communication device 6. The

communication system 4 includes the wireless communication

device 6. The management device 3 and the unmanned vehicle

2 wirelessly communicate with each other via the

communication system 4. The unmanned vehicle 2 travels on

a travel path HL at the work site based on travel condition

data transmitted from the management device 3.

[0013] [Unmanned Vehicle]

The unmanned vehicle 2 includes a vehicle main body 21,

a dump body 22 supported by the vehicle main body 21, a

traveling device 23 that supports the vehicle main body 21,

a speed sensor 24, an azimuth sensor 25, a position sensor

26, a wireless communication device 28, and a control

device 10.

[0014] The vehicle main body 21 includes a vehicle body

frame and supports the dump body 22. The dump body 22 is a

member on which a cargo is loaded.

[0015] The traveling device 23 includes wheels 27 and

travels on the travel path HL. The wheels 27 include front

wheels 27F and rear wheels 27R. Tires are mounted on the

wheels 27. The traveling device 23 has a drive device 23A,

a brake device 23B, and a steering device 23C.

[0016] The drive device 23A generates a driving force

for accelerating the unmanned vehicle 2. The drive device

23A includes an internal combustion engine such as a diesel

engine. Note that the drive device 23A may include an

electric motor. The driving force generated by the drive

device 23A is transmitted to the rear wheel 27R so that the

rear wheels 27R rotate. The unmanned vehicle 2 travels

autonomously as the rear wheels 27R rotate. The brake

device 23B generates a braking force for decelerating or

Docket No. PKOA-20376-US,AU: Final draft 5

stopping the unmanned vehicle 2. The steering device 23C

can adjust a traveling direction of the unmanned vehicle 2.

The traveling direction of the unmanned vehicle 2 includes

an azimuth of the front part of the vehicle main body 21.

The steering device 23C adjusts the traveling direction of

the unmanned vehicle 2 by steering the front wheels 27F.

[0017] The speed sensor 24 detects a travel speed of the

unmanned vehicle 2. Detection data of the speed sensor 24

includes travel speed data indicating the travel speed of

the traveling device 23.

[0018] The azimuth sensor 25 detects an azimuth of the

unmanned vehicle 2. Detection data of the azimuth sensor

25 includes azimuth data indicating the azimuth of the

unmanned vehicle 2. The azimuth of the unmanned vehicle 2

is a traveling direction of the unmanned vehicle 2. The

azimuth sensor 25 includes a gyro sensor, for example.

[0019] The position sensor 26 detects a position of the

unmanned vehicle 2 traveling on the travel path HL.

Detection data of the position sensor 26 includes absolute

position data indicating an absolute position of the

unmanned vehicle 2. The absolute position of the unmanned

vehicle 2 is detected using a global navigation satellite

system (GNSS). The global navigation satellite system

includes a global positioning system (GPS). The position

sensor 26 includes a GPS receiver. The global navigation

satellite system detects the absolute position of the

unmanned vehicle 2 specified by coordinate data of the

longitude, latitude, and altitude. The absolute position

of the unmanned vehicle 2 specified in a global coordinate

system is detected by the global navigation satellite

system. The global coordinate system is a coordinate

system fixed to the earth.

[0020] The wireless communication device 28 wirelessly

Docket No. PKOA-20376-US,AU: Final draft 6

communicates with the wireless communication device 6

connected to the management device 3. The communication

system 4 includes the wireless communication device 28.

[0021] The control device 10 includes a computer system

and is arranged in the vehicle main body 21. The control

device 10 outputs control commands to control traveling of

the traveling device 23 of the unmanned vehicle 2. The

control commands output from the control device 10 include

an accelerator command to operate the drive device 23A, a

brake command to operate the brake device 23B and a

steering command to operate the steering device 23C. The

drive device 23A generates a driving force for accelerating

the unmanned vehicle 2 based on the accelerator command

output from the control device 10. The brake device 23B

generates a braking force for decelerating or stopping the

unmanned vehicle 2 based on the brake command output from

the control device 10. The steering device 23C generates a

swinging force for changing a direction of the front wheels

27F so as to make the unmanned vehicle 2 travel straight or

swing based on the steering command output from the control

device 10.

[0022] [Travel Path]

FIG. 2 is a view schematically illustrating the

unmanned vehicle 2 and the travel path HL according to the

present embodiment. The travel path HL leads to a

plurality of work sites PA in the mine. The work sites PA

include at least one of a loading site PAl and a

discharging site PA2. An intersection IS is provided on

the travel path HL.

[0023] The loading site PAl refers to an area where

loading work for loading the cargo on the unmanned vehicle

2 is performed. At the loading site PA1, a loader 7 such

as a hydraulic excavator operates. The discharging site

Docket No. PKOA-20376-US,AU: Final draft 7

PA2 refers to an area where discharging work for

discharging the cargo from the unmanned vehicle 2 is

performed. For example, a crusher 8 is provided at the

discharging site PA2.

[00241 The management device 3 sets a travel condition

of the unmanned vehicle 2 on the travel path HL. The

unmanned vehicle 2 travels on the travel path HL based on

travel condition data that specifies the travel condition

transmitted from the management device 3.

[0025] The travel condition data that specifies the

travel condition of the unmanned vehicle 2 includes target

position x and y, a target travel speed Vr, a target

azimuth 0, and a target travel course CS of the unmanned

vehicle 2.

[0026] As illustrated in FIG. 2, the travel condition

data includes a plurality of travel points PI set on the

travel path HL at intervals. The interval between the

travel points PI is set to, for example, 1 [m]. Note that

the interval between the travel points PI may be set in the

range between 1 [m] and 5 [m]. The travel point PI

specifies the target positions x and y of the unmanned

vehicle 2.

[0027] The target travel speed Vr and the target azimuth

0 are set for each of the plurality of travel points PI. The target travel course CS is specified by a line

connecting the plurality of travel points PI.

[0028] That is, the travel condition data that specifies

the travel condition of the unmanned vehicle 2 includes the

plurality of travel points PI indicating the target

positions x and y of the unmanned vehicle 2, and the target

travel speed Vr and the target azimuth 0 of the unmanned

vehicle 2 at each of the plurality of travel points PI.

Docket No. PKOA-20376-US,AU: Final draft 8

[0029] The target positions x and y of the unmanned

vehicle 2 refers to target positions of the unmanned

vehicle 2 specified in the global coordinate system. That

is, the target positions x and y refer to the target

positions in the coordinate data specified by the longitude,

latitude and altitude. The target position x refers to a

target position in longitude (x-coordinate). The target

position y refers to a target position in latitude (y

coordinate). Note that the target positions x and y of the

unmanned vehicle 2 may be specified in a local coordinate

system of the unmanned vehicle 2.

[0030] The target travel speed Vr of the unmanned

vehicle 2 refers to a target travel speed of the unmanned

vehicle 2 at the time of traveling at (passing through) the

travel point PI. When the target travel speed Vr at a

first travel point PI is set to a first target travel speed

Vrl, the drive device 23A or the brake device 23B of the

unmanned vehicle 2 is controlled such that an actual travel

speed Vs of the unmanned vehicle 2 at the time of traveling

on the first travel point PI is the first target travel

speed Vrl. When the target travel speed Vr at a second

travel point PI is set to a second target travel speed Vr2,

the drive device 23A or the brake device 23B of the

unmanned vehicle 2 is controlled such that the actual

travel speed Vs of the unmanned vehicle 2 at the time of

traveling on the second travel point PI is the second

target travel speed Vr2.

[0031] The target azimuth 0 of the unmanned vehicle 2

refers to a target azimuth of the unmanned vehicle 2 at the

time of traveling at (passing through) the travel point PI.

In addition, the target azimuth 0 refers to an azimuth

angle of the unmanned vehicle 2 with respect to the

reference azimuth (for example, north). In other words,

Docket No. PKOA-20376-US,AU: Final draft 9

the target azimuth 0 is a target azimuth of the front part

of the vehicle main body 21, and indicates a target

traveling direction of the unmanned vehicle 2. When the

target azimuth 0 at the first travel point PI is set to a

first target azimuth 01, the steering device 23C of the

unmanned vehicle 2 is controlled such that an actual

azimuth Os of the unmanned vehicle 2 at the time of

traveling on the first travel point PI is the first target

azimuth 01. When the target azimuth 0 at the second travel

point PI is set to a second target azimuth 02, the steering

device 23C of the unmanned vehicle 2 is controlled such

that the actual azimuth Os of the unmanned vehicle 2 at the

time of traveling on the second travel point PI is the

second target azimuth 02.

[0032] [Control System]

FIG. 3 is a functional block diagram illustrating a

control system of the unmanned vehicle 2 according to the

present embodiment. The control system includes the

control device 10 and the management device 3. The control

device 10 can communicate with the management device 3 via

the communication system 4.

[0033] The management device 3 includes a travel

condition data generation unit 31 and an interface unit 32.

The travel condition data generation unit 31 generates

travel condition data that specifies a travel condition of

the unmanned vehicle 2. The interface unit 32 is connected

to each of an input device 33, an output device 34, and the

wireless communication device 6. The input device 33, the

output device 34, and the wireless communication device 6

are installed in the control facility 5. The travel

condition data generation unit 31 communicates with each of

the input device 33, the output device 34, and the wireless

Docket No. PKOA-20376-US,AU: Final draft 10

communication device 6 via the interface unit 32.

[0034] The input device 33 is operated by the controller

of the control facility 5 to generate input data. The

input data generated by the input device 33 is output to

the management device 3. The management device 3 acquires

the input data from the input device 33. As the input

device 33, a contact-type input device that is operated by

the controller's hand, such as a computer keyboard, a mouse,

a touch panel, an operation switch, and an operation button,

is exemplified. Note that the input device 33 may be a

voice input device operated by the controller's voice.

[0035] The output device 34 provides output data to the

controller of the control facility 5. The output device 34

may be a display device that outputs display data, a

printing device that outputs print data, or a voice output

device that outputs voice data. As the display device, a

flat panel display, such as a liquid crystal display (LCD)

and an organic electroluminescence display (OELD), is

exemplified.

[0036] The travel condition is determined by, for

example, the controller existing in the control facility 5.

The controller operates the input device 33 connected to

the management device 3. The travel condition data

generation unit 31 generates the travel condition data

based on the input data generated by operating the input

device 33. The interface unit 32 transmits the travel

condition data to the unmanned vehicle 2 via the

communication system 4. The control device 10 of the

unmanned vehicle 2 acquires the travel condition data

transmitted from the management device 3 via the

communication system 4.

[0037] The control device 10 includes an interface unit

11, a travel condition data acquisition unit 12, a travel

Docket No. PKOA-20376-US,AU: Final draft 11

condition change unit 13, a travel control unit 14, a

threshold storage unit 15, a threshold change unit 16, and

a notification unit 17.

[00381 The interface unit 11 is connected to each of the

speed sensor 24, the azimuth sensor 25, the position sensor

26, the traveling device 23, and the wireless communication

device 28. The interface unit 11 communicates with each of

the speed sensor 24, the azimuth sensor 25, the position

sensor 26, the traveling device 23, and the wireless

communication device 28.

[00391 The travel condition data acquisition unit 12

acquires the travel condition data transmitted from the

management device 3 via the interface unit 11.

[0040] The travel condition change unit 13 outputs a

change command to change the travel condition specified by

the travel condition data based on a difference AO in the

target azimuth 0 between adjacent travel points PI

specified in the travel condition data. The travel

condition data that specifies the travel condition of the

unmanned vehicle 2 includes the target azimuth 0 of the

unmanned vehicle 2 at each of the plurality of travel

points PI. The travel condition change unit 13 calculates

the difference AO in the target azimuths 0 between the

adjacent travel points PI based on the travel condition

data acquired by the travel condition data acquisition unit

12. The travel condition change unit 13 outputs the change

command to change the travel condition specified by the

travel condition data based on the calculated difference AO

in the target azimuth 0.

[0041] FIG. 4 is a schematic view for describing the

travel condition of the unmanned vehicle 2 according to the

present embodiment, and is the view schematically

Docket No. PKOA-20376-US,AU: Final draft 12

illustrating a plurality of travel points PI set at the

intersection IS of the travel path HL. FIG. 4 illustrates

an example in which the target travel course CS is set such

that the unmanned vehicle 2 turns right at the intersection

IS.

[0042] In the example illustrated in FIG. 4, the

plurality of travel points PI (PI(1), PI(2), PI(3),..., and

PI(i)) are specified at the intersection IS. The target

positions x and y, the target travel speed Vr, and the

target azimuth 0 are set for each of the plurality of

travel points PI.

[0043] Target positions x(1) and y(l), a target travel

speed Vr(1), and a target azimuth 0(1) are set at the

travel point PI(1). Target positions x(2) and y(2), a

target travel speed Vr(2), and a target azimuth 0(2) are

set at the travel point PI(2). Similarly, target positions

x(3) and y(3), a target travel speed Vr(3), and a target

azimuth 0(3) are set at the travel point PI(3). Target

positions x(i) and y(i), a target travel speed Vr(i), and a

target azimuth 0(i) are set at the travel point PI(i).

[0044] FIG. 5 is a schematic view for describing the

travel condition of the unmanned vehicle 2 according to the

present embodiment, and is the view obtained by extracting

some travel points PI. The travel point PI(i) and the

travel point PI(i-1) are adjacent to each other. In the

example illustrated in FIG. 5, the travel condition change

unit 13 calculates a difference AO(i) between the target

azimuth 0(i) of the travel point PI(i) and the target

azimuth 0(i-1) of the travel point PI(i-1). The difference

AO(i) is calculated by calculation [0(i) - 0(i-1)].

[0045] In the example illustrated in FIG. 4, the travel

point PI(2) and the travel point PI(1) are adjacent to each

Docket No. PKOA-20376-US,AU: Final draft 13

other. A difference AO(2) between the target azimuth 0(2)

of the travel point PI(2) and the target azimuth 0(1) of

the travel point PI(1) is calculated by calculation [0(2)

0(1)]. The travel point PI(3) and the travel point PI(2)

are adjacent to each other. A difference A0(3) between the

target azimuth 0(3) of the travel point PI(3) and the

target azimuth 0(2) of the travel point PI(2) is calculated

by calculation [0(3) - 0(2)]. In the example illustrated

in FIG. 4, the difference A0(2) is larger than the

difference AO(3).

[0046] Note that the travel condition data generation

unit 31 does not necessarily set the target azimuth 0 at

the travel point PI. When the travel condition data that

specifies the travel point PI at which the target azimuth 0

has not been set is transmitted from the management device

3 to the control device 10, the travel condition change

unit 13 can calculate the target azimuth 0 based on the

target positions x and y at the travel point PI. For

example, when a distance of the x-coordinate between the

travel point PI(i) and the travel point PI(i-1), which are

adjacent, is dx(i) and a distance of the y-coordinate

between the travel point PI(i) and the travel point PI(i-1),

which are adjacent, is dy(i), dx(i) and dy(i) are expressed

by the following Formulas (1) and (2).

[0047]

dx(i) = x(i) - x(i - 1) (1)

dy(i) = y(i) - y(i - 1) (2)

[0048] The target azimuth 0(i) is represented by the

Docket No. PKOA-20376-US,AU: Final draft 14

arctangent of a difference between dx(i) and dy(i). That

is, the target azimuth 0(i) is expressed by the following

Formula (3).

[0049]

0(i) = arctan[dy(i)/dx(i)] (3)

[0050] The travel condition change unit 13 calculates

the difference AO in the target azimuth 0 between the

adjacent travel points PI, and then, outputs the change

command when determining that the difference AO is equal to

or larger than a threshold SO. The threshold SO is a

threshold related to the difference AO in the target

azimuth 0, is a predetermined value, and is stored in the

threshold storage unit 15. The travel condition change

unit 13 compares the difference AO with the threshold SO,

and outputs the change command to change the travel

condition specified by the travel condition data when

determining that the difference AO is equal to or larger

than the threshold SO.

[0051] The change command includes lowering the actual

travel speed Vs of the unmanned vehicle 2 below the target

travel speed Vr. For example, in the example illustrated

in FIG. 4, when the difference AO(2) between the target

azimuth 0(2) of the travel point PI(2) and the target

azimuth 0(1) of the travel point PI(1) is equal to or

larger than the threshold SO, the travel condition change

unit 13 outputs the change command such that the actual

travel speed Vs when the unmanned vehicle 2 travels at the

travel point PI(2) is lower than the target travel speed

Vr(2) set at the travel point PI(2).

[0052] The travel control unit 14 outputs the control

Docket No. PKOA-20376-US,AU: Final draft 15

command to control the traveling of the unmanned vehicle 2

to the traveling device 23 based on the change command

output from the travel condition change unit 13. For

example, in a case where the change command is output such

that the actual travel speed Vs when the unmanned vehicle 2

travels at the travel point PI(2) is lower than the target

travel speed Vr(2) set at the travel point PI(2), the

travel control unit 14 outputs the control command to the

traveling device 23 such that the unmanned vehicle 2

travels at the travel speed Vs lower than the target travel

speed Vr(2), instead of the target travel speed Vr(2), when

traveling at the travel point PI(2).

[00531 Note that the change command may include setting

the actual travel speed Vs of the unmanned vehicle 2 to

zero. In the example illustrated in FIG. 4, when the

difference AO(2) between the target azimuth 0(2) of the

travel point PI(2) and the target azimuth 0(1) of the

travel point PI(1) is equal to or larger than the threshold

SO, the travel condition change unit 13 may output the

change command such that the unmanned vehicle 2 stops at

the travel point PI(2). The travel control unit 14 may

output the control command to the traveling device 23 based

on the change command output from the travel condition

change unit 13 such that the unmanned vehicle 2 stops when

the unmanned vehicle 2 travels at the travel point PI(2).

[0054] In addition, the travel control unit 14 also

controls the traveling device 23 such that the unmanned

vehicle 2 travels according to the target travel course CS.

In the present embodiment, the travel control unit 14

controls traveling of the unmanned vehicle 2 based on dead

reckoning navigation. The dead reckoning navigation refers

to navigation in which traveling is performed while

Docket No. PKOA-20376-US,AU: Final draft 16

estimating a current position of the unmanned vehicle 2

based on a moving distance and an azimuth (azimuth change

amount) of the unmanned vehicle 2 from a starting point

whose longitude and latitude are known. The moving

distance of the unmanned vehicle 2 is detected by the speed

sensor 24. The azimuth of the unmanned vehicle 2 is

detected by the azimuth sensor 25. The travel control unit

14 acquires the detection data of the speed sensor 24 and

the detection data of the azimuth sensor 25 to calculate

the moving distance and the azimuth change amount of the

unmanned vehicle (2) from the known starting point, and

controls the traveling device (23) while estimating the

current position of the unmanned vehicle (2). In the

following description, the current position of the unmanned

vehicle 2, which is estimated based on the detection data

of the speed sensor 24 and the detection data of the

azimuth sensor 25, is appropriately referred to as an

estimated position.

[00551 In the dead reckoning navigation, the travel

control unit 14 calculates the estimated position of the

unmanned vehicle 2 based on the detection data of the speed

sensor 24 and the detection data of the azimuth sensor 25

to control the traveling device 23 such that the unmanned

vehicle 2 travels according to the target travel course CS.

In the dead reckoning navigation, an error is likely to

occur between the estimated position and an actual position

of the unmanned vehicle 2 due to accumulation of detection

errors of one or both of the speed sensor 24 and the

azimuth sensor 25 if a traveling distance of the unmanned

vehicle 2 becomes long. As a result, the unmanned vehicle

2 may deviate from the target travel course CS.

[00561 In the present embodiment, the travel control

unit 14 corrects the estimated position of the unmanned

Docket No. PKOA-20376-US,AU: Final draft 17

vehicle 2 traveling by the dead reckoning navigation based

on the detection data of the position sensor 26. That is,

the travel control unit 14 causes the unmanned vehicle 2 to

travel while correcting the estimated position of the

unmanned vehicle 2 traveling by the dead reckoning

navigation using a detected position (absolute position) of

the unmanned vehicle 2 detected by the position sensor 26.

[0057] The travel condition change unit 13 does not

output the change command when determining that the

difference AO in the target azimuth 0 is smaller than the

threshold SO. When the difference AO in the target azimuth

O is smaller than the threshold OS, the travel control unit 14 outputs the control command to the traveling device 23

such that the unmanned vehicle 2 travels based on the

travel condition specified by the travel condition data.

For example, when the difference AO(2) between the target

azimuth 0(3) of the travel point PI(3) and the target

azimuth 0(2) of the travel point PI(2) is smaller than the

threshold SO in the example illustrated in FIG. 4, the

travel condition change unit 13 does not output the change

command. When the unmanned vehicle 2 travels at the travel

point PI(3), the travel control unit 14 outputs the control

command such that the vehicle travels at the target travel

speed Vr(3) set at the travel point PI(3).

[0058] The threshold change unit 16 changes the

threshold SO based on the target travel speed Vr set at the

travel point PI. The threshold change unit 16 decreases

the threshold SO as the target travel speed Vr set at the

travel point PI increases. The travel condition change

unit 13 outputs the change command based on the threshold

SO determined by the threshold change unit 16.

Docket No. PKOA-20376-US,AU: Final draft 18

[00591 In the present embodiment, the threshold change

unit 16 changes the threshold SO based on an expression

illustrated in Formula (4). In Formula (4), Vr is the

target travel speed set at the travel point PI. Ro is a

minimum turning radius of the unmanned vehicle 2. u is a

constant.

[00601

SO = arctan(1/Ro)+ a x arctan(1/Vr) (4)

[00611 Note that the threshold storage unit 15 may store

table data indicating the relationship between the target

travel speed Vr and the threshold SO. The threshold change

unit 16 may change the threshold SO based on the target

travel speed Vr derived from the travel condition data and

the table data stored in the threshold storage unit 15.

[00621 FIG. 6 is a schematic view for describing the

threshold SO according to the present embodiment. As

illustrated in FIG. 6, the table data indicating the

relationship between the target travel speed Vr and the

threshold SO may be set and stored in the threshold storage

unit 15. As illustrated in FIG. 6, the threshold SO is set

to a smaller value as the target travel speed Vr set at the

travel point PI is higher.

[00631 When the change command is output from the travel

condition change unit 13, the notification unit 17 outputs

notification data indicating that the change command has

been output. The notification data output from the

notification unit 17 is transmitted to the management

device 3 via the communication system 4. The notification

data may include display data to be displayed on a display

device connected to the management device 3 and voice data

Docket No. PKOA-20376-US,AU: Final draft 19

to be output from a voice output device connected to the

management device 3. That is, the display data indicating

that the change command has been output may be displayed on

the display device of the control facility 5, and the voice

data indicating that the change command has been output may

be output from the voice output device of the control

facility 5.

[0064] [Control Method]

Next, a method for controlling the unmanned vehicle 2

according to the present embodiment will be described. FIG.

7 is a flowchart illustrating a method for controlling the

unmanned vehicle 2 according to this embodiment.

[0065] Travel condition data is transmitted from the

management device 3 to the control device 10. The travel

condition data acquisition unit 12 acquires the travel

condition data transmitted from the management device 3

(Step ST1).

[0066] The travel control unit 14 outputs a control

command to control the traveling device 23 such that the

unmanned vehicle 2 travels according to a travel condition

specified by the travel condition data.

[0067] The travel condition change unit 13 determines

whether the unmanned vehicle 2 traveling according to the

travel condition is traveling at the intersection IS (Step

ST2).

[0068] The travel condition change unit 13 can determine

whether the unmanned vehicle 2 traveling according to the

travel condition is traveling at the intersection IS, for

example, based on the target positions x and y set at the

travel point PI. Note that the travel condition data

generation unit 31 may add intersection data indicating

that the intersection IS specified to the travel point PI.

The travel condition change unit 13 may determine whether

Docket No. PKOA-20376-US,AU: Final draft 20

the unmanned vehicle 2 traveling according to the travel

condition is traveling at the intersection IS based on the

intersection data.

[00691 If determining that the unmanned vehicle 2 is

traveling at the intersection IS in Step ST2 (Step ST2:

Yes), the travel condition change unit 13 calculates the

difference AO in the target azimuth 0 between the adjacent

travel points PI at the intersection IS (Step ST3).

[0070] The threshold change unit 16 determines the

threshold SO based on the target travel speed Vr set at the

travel point PI (Step ST4).

[0071] The travel condition change unit 13 determines

whether the difference AO in the target azimuth 0

calculated in Step ST3 is equal to or larger than the

threshold SO determined in Step ST4 (Step ST5).

[0072] If determining that the difference AO is equal to

or larger than the threshold SO in Step ST5 (Step ST5: Yes),

the travel condition change unit 13 outputs a change

command to change the travel condition specified by the

travel condition data (Step ST6).

[0073] The change command includes lowering the travel

speed Vs of the unmanned vehicle 2 below the target travel

speed Vr. In the present embodiment, the change command

includes setting the travel speed Vs of the unmanned

vehicle 2 to zero. The travel condition change unit 13

outputs the change command to set the target travel speed

Vr of the unmanned vehicle 2, which passes through the

travel point PI determined to have the difference AO equal

to or larger than the threshold SO, to zero.

[0074] The travel control unit 14 outputs a control

command to control traveling of the unmanned vehicle 2

based on the change command output from the travel

Docket No. PKOA-20376-US,AU: Final draft 21

condition change unit 13 (Step ST7).

[0075] That is, the travel control unit 14 controls the

traveling of the unmanned vehicle 2 based on the travel

condition changed by the change command. In the present

embodiment, the travel control unit 14 outputs the control

command such that the unmanned vehicle 2 stops at the

travel point PI where the target travel speed Vr is set to

zero. As a result, the unmanned vehicle 2 stops at the

intersection IS. The unmanned vehicle 2 can be stopped on

the target travel course CS without deviating from the

target travel course CS.

[0076] For example, when the difference AO(2) between

the target azimuth 0(2) of the travel point PI(2) and the

target azimuth 0(1) of the travel point PI(1) is equal to

or larger than the threshold SO in the example illustrated

in FIG. 4, the unmanned vehicle 2 stops at the travel point

PI(2).

[0077] The notification unit 17 outputs notification

data indicating that the change command has been output

from the travel condition change unit 13 (Step ST8).

[0078] The notification data output from the

notification unit 17 is transmitted to the management

device 3 via the communication system 4. The management

device 3 causes the output device 34 to output the

notification data. The controller existing in the control

facility 5 can recognize that the unmanned vehicle 2 has

stopped at the intersection IS based on the notification

data output from the output device 34.

[0079] The controller operates the input device 33 to

recreate travel condition data. The travel condition data

generation unit 31 recreates the travel condition data such

that the target travel speed Vr set at the travel point PI

Docket No. PKOA-20376-US,AU: Final draft 22

of the intersection IS becomes low, for example. The

controller recreates the travel condition data such that

the target travel course CS draws a gentle curve. The

regenerated travel condition data is transmitted to the

control device 10 of the unmanned vehicle 2 via the

communication system 4. The travel control unit 14 of the

control device 10 restarts traveling of the unmanned

vehicle 2 based on the transmitted travel condition data.

Since the unmanned vehicle 2 does not deviate from the

target travel course CS, the traveling can be restarted at

an early stage.

[00801 If determining that the unmanned vehicle 2 is not

traveling at the intersection IS in Step ST2 (Step ST2: No)

and if determining that the difference AO is smaller than

the threshold SO in Step ST5 (Step ST5: No), the travel

control unit 14 outputs the control command to control the

traveling of the unmanned vehicle 2 such that the unmanned

vehicle 2 travels according to the travel condition

specified by the travel condition data acquired by the

travel condition data acquisition unit 12 (Step ST9).

[0081] [Computer System]

FIG. 8 is a block diagram illustrating an example of a

computer system 1000. Each of the management device 3 and

the control device 10 described above includes the computer

system 1000. The computer system 1000 includes: a

processor 1001 such as a central processing unit (CPU); a

main memory 1002 including a nonvolatile memory such as a

read only memory (ROM) and a volatile memory such as a

random access memory (RAM); a storage 1003; and an

interface 1004 including an input/output circuit. The

functions of the management device 3 and the functions of

the control device 10 described above are stored in the

storage 1003 as programs. The processor 1001 reads the

Docket No. PKOA-20376-US,AU: Final draft 23

program from the storage 1003, expands the read program in

the main memory 1002, and executes the above-described

processing according to the program. Note that the program

may be delivered to the computer system 1000 via a network.

[0082] [Effect]

As described above, the difference AO in the target

azimuth 0 between the adjacent travel points PI is

calculated when the unmanned vehicle 2 travels at the

intersection IS in the case where the travel condition data

is transmitted from the control facility 5 to the unmanned

vehicle 2 according to the present embodiment. When the

difference AO in the target azimuth 0 is equal to or larger

than the threshold SO, the change command to change the

travel condition is output such that the travel speed Vs of

the unmanned vehicle 2 becomes lower than the target travel

speed Vr, and thus, the unmanned vehicle 2 is prevented

from deviating from the target travel course CS. Therefore,

a decrease in productivity at the work site is suppressed.

[0083] The difference AO represents the turning radius

of the unmanned vehicle 2 when turning at the intersection

IS or turning a curve of the travel path HL. The large

difference AO represents that the turning radius of the

unmanned vehicle 2 is small. That is, the large difference

AO represents that the unmanned vehicle 2 turns a steep curve. If the target travel speed Vr set at the travel

point PI is high in the case where the difference AO is

large, the unmanned vehicle 2 travels at a high speed on a

steep curve. If the target travel speed Vr is high despite

the large difference AO, the unmanned vehicle 2 is highly

likely to deviate from the target travel course CS. If the

unmanned vehicle 2 deviates from the target travel course

CS and the operation of the unmanned vehicle 2 is stopped,

Docket No. PKOA-20376-US,AU: Final draft 24

the productivity at the work site is likely to decrease.

[0084] In the present embodiment, when it is determined

that the unmanned vehicle 2 is highly likely to deviate

from the target travel course CS based on the difference AO

in the target azimuth 0, the travel condition specified by

the travel condition data is changed such that the unmanned

vehicle 2 does not deviate from the target travel course CS.

The unmanned vehicle 2 travels according to the travel

condition after being changed based on the change command,

and thus, is prevented from deviating from the target

travel course CS.

[0085] In the present embodiment, the difference AO in

the target azimuth 0 and the threshold SO are compared, and

the travel condition specified by the travel condition data

is changed when the difference AO is equal to or larger

than the threshold SO. On the other hand, when the

difference AO in the target azimuth 0 is smaller than the

threshold SO, the travel condition specified by the travel

condition data is not changed, and the unmanned vehicle 2

travels based on the travel condition generated by the

management device 3. When the difference AO in the target

azimuth 0 is smaller than the threshold SO, that is, when

the possibility that the unmanned vehicle 2 deviates from

the target travel course CS is low, the unmanned vehicle 2

can travel at a high speed based on the travel condition

generated by the management device 3. As a result, the

decrease in productivity at the work site is suppressed.

[0086] In the present embodiment, the threshold SO is

changed based on the target travel speed Vr. The threshold

SO is set to a smaller value as the target travel speed Vr

is higher. That is, even when the unmanned vehicle 2 turns

Docket No. PKOA-20376-US,AU: Final draft 25

a gentle curve, the travel condition is changed such that

the travel speed Vs of the unmanned vehicle 2 becomes low

when the target travel speed Vr is high. This prevents the

unmanned vehicle 2 from deviating from the target travel

course CS.

[0087] [Other Embodiments]

In the above embodiment, the difference AO in the

target azimuth 0 between the adjacent travel points PI is

calculated, and the change command is output based on the

calculated difference AO. For example, a change command

may be output based on a difference in the target azimuth 0

among three or more travel points PI, and a change command

may be output based on a difference in the target azimuth 0

among a plurality of travel points PI which are not

adjacent to each other (for example, every other travel

point PI). That is, the travel condition change unit 13

may output the change command to change the travel

condition specified by the travel condition data based on

the difference in the target azimuth 0 among the plurality

of travel points PI.

[0088] In the above embodiment, the threshold SO is

changed based on the target travel speed Vr. The threshold

SO may be a variable value or a fixed value.

[0089] In the above embodiment, the unmanned vehicle 2

stops on the target travel course CS when it is determined

that the difference AO is equal to or larger than the

threshold SO. As described above, the unmanned vehicle 2

may travel at a speed lower than the target travel speed Vr

when it is determined that the difference AO is equal to or

larger than the threshold SO. Since the unmanned vehicle 2

travels at the speed lower than the target travel speed Vr,

Docket No. PKOA-20376-US,AU: Final draft 26

deviation from the target travel course CS is suppressed.

[00901 In the above embodiment, the travel condition

change unit 13 compares the difference AO and the threshold

SO. The travel condition change unit 13 does not

necessarily compare the difference AO and the threshold SO.

For example, the travel condition change unit 13 may lower

the target travel speed Vr as the difference AO is larger,

and may increase the target travel speed Vr as the

difference AO is smaller.

[0091] Note that at least some of the functions of the

control device 10 may be provided in the management device

3, and at least some of the functions of the management

device 3 may be provided in the control device 10, in the

above embodiment. For example, the management device 3 may

have the function of the travel condition change unit 13

such that travel condition data that specifies a travel

condition after being changed by the management device 3

based on a change command may be transmitted to the control

device 10 of the unmanned vehicle 2 via the communication

system 4, in the above embodiment. The travel control unit

14 of the control device 10 controls the traveling of the

unmanned vehicle 2 based on the changed travel condition

data.

Reference Signs List

[0092] 1 MANAGEMENT SYSTEM

2 UNMANNED VEHICLE

3 MANAGEMENT DEVICE

4 COMMUNICATION SYSTEM

5 CONTROL FACILITY

6 WIRELESS COMMUNICATION DEVICE

7 LOADER

8 CRUSHER

Docket No. PKOA-20376-US,AU: Final draft 27

10 CONTROL DEVICE

11 INTERFACE UNIT

12 TRAVEL CONDITION DATA ACQUISITION UNIT

13 TRAVEL CONDITION CHANGE UNIT

14 TRAVEL CONTROL UNIT

15 THRESHOLD STORAGE UNIT

16 THRESHOLD CHANGE UNIT

17 NOTIFICATION UNIT

21 VEHICLE MAIN BODY

22 DUMP BODY

23 TRAVELING DEVICE

23A DRIVE DEVICE

23B BRAKE DEVICE

23C STEERING DEVICE

24 SPEED SENSOR

25 AZIMUTH SENSOR

26 POSITION SENSOR

27 WHEEL

27F FRONT WHEEL

27R REAR WHEEL

28 WIRELESS COMMUNICATION DEVICE

31 TRAVEL CONDITION DATA GENERATION UNIT

32 INTERFACE UNIT

33 INPUT DEVICE

34 OUTPUT DEVICE

CS TARGET TRAVEL COURSE HL TRAVEL PATH IS INTERSECTION PA WORK SITE

PA1 LOADING SITE

PA2 DISCHARGING SITE

PI TRAVEL POINT

Claims (6)

1. An unmanned vehicle control system comprising:

a travel condition data acquisition unit that acquires

travel condition data specifying a travel condition of an

unmanned vehicle, the travel condition data including a

target travel speed and a target azimuth of the unmanned

vehicle at each of a plurality of travel points;

a travel condition change unit that outputs a change

command to change the travel condition specified by the

travel condition data based on a difference in the target

azimuth among the plurality of travel points; and

a travel control unit that outputs a control command

to control traveling of the unmanned vehicle based on the

change command,

wherein the travel condition change unit outputs the

change command when the difference in the target azimuth is

equal to or larger than a threshold, and

the travel control unit outputs the control command

such that the unmanned vehicle travels based on the travel

condition data when the difference in the target azimuth is

smaller than the threshold.

2. The unmanned vehicle control system according to claim

1, further comprising

a threshold change unit that changes the threshold

based on the target travel speed, wherein

the travel condition change unit outputs the change

command based on the threshold determined by the threshold

change unit.

3. The unmanned vehicle control system according to claim

2, wherein the threshold change unit decreases the threshold as the target travel speed increases.

4. The unmanned vehicle control system according to any

one of claims 1 to 3, wherein

the change command includes lowering a travel speed of

the unmanned vehicle below the target travel speed.

5. An unmanned vehicle comprising the unmanned vehicle

control system according to any one of claims 1 to 4.

6. An unmanned vehicle control method comprising:

acquiring travel condition data that specifies a

travel condition of an unmanned vehicle, the travel

condition data including a target travel speed and a target

azimuth of the unmanned vehicle at each of a plurality of

travel points;

outputting a change command to change the travel

condition specified by the travel condition data based on a

difference in the target azimuth among the plurality of

travel points; and

outputting a control command to control traveling of

the unmanned vehicle based on the change command,

wherein the change command is output when the

difference in the target azimuth is equal to or larger than

a threshold, and

wherein the control command is output such that the

unmanned vehicle travels based on the travel condition data

when the difference in the target azimuth is smaller than

the threshold.

PKOA-20376-PCT

PKOA-20376-PCT

24 25 26

SPEED AZIMUTH POSITION 33 SENSOR SENSOR SENSOR

INPUT DEVICE

3 10

MANAGEMENT DEVICE CONTROL DEVICE

31 32 9 28 11 12 6 TRAVEL CONDITION INTERFACE INTERFACE TRAVEL CONDITION DATA DATA GENER- UNIT UNIT ACQUISITION UNIT ATION UNIT 15 17 13 16

NOTIFICA- TRAVEL THRESHOLD CONDITION CHANGE THRESHOLD TION UNIT CHANGE UNIT UNIT STORAGE 34 UNIT OUTPUT DEVICE 14

TRAVEL CONTROL UNIT

23

TRAVELING DEVICE

23A DRIVE DEVICE

BRAKE DEVICE 23B

STEERING DEVICE 23C PKOA-20376-PCT

PKOA-20376-PCT

θ

θ

θ

PKOA-20376-PCT

θ

θ

PKOA-20376-PCT

θ

PKOA-20376-PCT

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